ui/Defs: corrected const order for string-literal ui::hash().
tty::TerminalInfo: prefixed all uses of fixed-size integral types with `std::`.
Prefixed all uses of fixed-size integral types with `std::`; retyped int to signed.

ErrorCode: doc tidy.
tty::Terminal: corrected use of duct::IO::dynamic_streambuf::commit_direct().¹

1: As per duct/a3ca2b47ec2896270619389df8be6e52e3621f79.